The present invention relates to a method and apparatus for printing polychromatic half-tone images by the employment of image points for different primary colors which are disposed at prescribed raster positions.
It is generally known to represent half-tone images consisting of image points with varying primary colors and varying size. As a function of the degree of coverage of the particular primary color, the size of the image points is changed. Such a manner of representing half-tone images is known, for example, from conventional matrix printing devices.
If the half-tone images are to be represented with image points of constant size, the conventional matrix printing methods and apparatus cannot be employed. The generation of polychromatic image points, for example, with an ink printing device was proposed in German patent application P 29 25 812.6 (not laid open). This ink printing device contains an ink printing head with a plurality of nozzles of which selected nozzles eject ink droplets of different colors.